Various Panels: Remove beta label from Bar Chart, Candlestick, Histogram, State Timeline, & Status History Panels

[codeincarnate]

This PR removes the beta label from a number of panels that are now fairly stable and in common usage.

[grafanabot]

Drone build failed: https://drone.grafana.net/grafana/grafana-enterprise/41666

[nmarrs]

When updating panel status (alpha, beta, stable) the api_plugins_test.go backend test will fail. To update it we need to first set the updateSnapshotFlag to true in that file (see here for context) and then run make test-go locally to update the snapshot / fix the failing test. Then we can commit the updated snapshot to the PR to fix the build 👍

Writing this out as a future guide for myself, as in the past I've gotten blocked by this / assuming the flag was passed via CLI or something 😬

[nmarrs]

If we are adding this to the change log, maybe we should explicitly name which panels are no longer in beta in the PR title 🤔

[grafanabot]

Drone build failed: https://drone.grafana.net/grafana/grafana-enterprise/41755

[grafanabot]

This pull request was removed from the 9.3.0-beta1 milestone because 9.3.0-beta1 is currently being released.